A series of studies are being conducted to determine the following: 1. What the effects of stimulants are on the speech and language production of language-disordered hyperactive boys; 2. whether auditory processing disorders in hyperactive boys with and without disorders in speech, language and reading respond similarly to the administration of dextroamphetamine; 3. whether the effects of stimulant drugs on auditory processing disorders in language-impaired children are related to the effects of stimulants on language processing and speech fluency; 4. whether auditory processing disorders are related to speech perception discrimination curves in hyperative boys with and without language disorders.